DNS: about the Domain Name System


DNS - domain name system, takes an address you type in and puts you in touch with the correct computer on the internet
Domain Name - an address on the internet; example: boblindquist.com, google.com
IP Address - the address of a computer on the Internet
ISP - internet service provider, the company that provides you with Internet access
Registrar - a company that sells domain names
Web Browser - a program you use to access web sites (Internet Explorer, Firefox, Safari)

What is a domain name and why should you care?

Most people are not aware of the DNS system, nor would many even want to know. It sounds like just another technical acronym for those computer nerds to throw at you to confuse you. That is not the case. If you have a web site or are considering getting one, you probably should start paying attention now.

I am going to attempt to sugar-coat some of the technical details. So if you are a hardcore computer user, please forgive the details that I leave out. When you pick up your phone to make a call and dial a number, you assume that you will be connected to the person you are calling. How do you know what phone number to dial? Many people use a phone book. Some people dial 411. Others maintain lists of their frequently dialed numbers.

Each computer on the Internet has something called an IP address. An IP address is a unique number that identifies your computer. Let us not worry about how one computer can reach out through the Internet and call another.

A domain name is an address on the Internet. An example of a domain name is google.com or boblindquist.com. When you type in a domain name in a web browser your computer reaches out and asks the DNS system for the address of that computer. Your computer then "calls" out to that IP address and you are on your way.

What is a registrar and why do I need one?

A registrar is a company that sells domain names. For a while, there was only one company that sold domain names. Now there are many companies that resell domain names. Basically, what a registrar does is keep a record for you. This record points to an address you specify. Your relationship with your registrar can end there. You can not purchase a name that someone else already has unless they forget or decline to renew it. If you think of a name that no one else has, you can register it and be on your way to establishing your Internet presence.

One warning, registrars will try to sell you a ton of things you do not need. Do not buy them. They will ask you if you want email addresses and if you want web hosting and if you want placement in search engines. Unless you want your registrar to be your hosting company, purchase only the domain name.

You need to find a domain name registrar. Network Solutions and GoDaddy are registrars that you may have heard of. You can register a domain name right now by visiting http://domains.boblindquist.com

Make sure to keep the username and password for your account with your registrar in a safe place.

WHOIS Information and Access to your Account

You are required to keep accurate information about who owns a domain name, such as your name, address, phone number and email address. Anyone can look up this information by doing what is called a WHOIS lookup. There are services you can purchase that protect your information from being gathered. I recommend hiding this information on all the domains you own. Many companies offer a service to protect your WHOIS information for an additional fee, where only your name is shown and they provide their address and telephone number. If someone sends them physical mail addressed to you, they will forward it on. If someone calls the phone number listed on the WHOIS, they are given a message telling them to send postal mail to their address. It can cut down on scams by not providing people with the details to contact you.

Many registrars allow you to specify other people who can access to your account. This is good in that you do not need to provide your username and password to someone in order for them to make changes to your domains. With Network Solutions, for example, you can specify someone as a technical contact and then they would have access to change the nameservers. If you specified someone as an administrative contact, they can purchase services and make other changes to the domain. While a trustworthy consultant would never steal your domain name or perform some other unscrupulous act, keeping your password secure and to yourself is another added measure of security.

Make sure your domain name is registered to you!

Always register your domain names in your own name. If you hire someone to make a web site, the domain name should the registered to you. If another party controls the domain name, they can restrict your access to it or even use it for their own purposes. You can find out who is listed as the owner of your domain name by doing a WHOIS lookup. If you google for "whois" you will find numerous sites that will allow you to perform this lookup. You also want to make sure that the email address listed for you is correct and that you have access to it.

As long as you have your domain name registered in your name and you keep your registrar username and password secure, your name should be safe. You could hire someone to develop a web site and decide to terminate your relationship with that person and you would not risk losing your domain name. If you hire someone to build you a site and they register the domain in their own name, there is a risk and they could withhold giving you access to the domain name.

How long do domain name registrations last?

Normally, you register a domain for a period of 1 year. You could also register it for a period of multiple years. You may not want to do it for too long of a term because if you buy it now for five years, you may totally forget about it in five years and lose your domain. Yet another reason to keep your contact information up to date, your registrar will email you and tell you when your name is expiring. If your name is only slightly expired, you may still be able to renew it with your registrar. They call this a "redemption period".

There is a vicious practice that goes on now with regards to expired domain names. There are many companies out there that automatically "grab" any expired domains as soon as they are "released" and will then hold them for ransom or auction them off to the highest bidder. The best way to avoid this is to make sure your domain names always get renewed. If someone else has a name you are interested in, you can also pay some of these companies to try to grab it for you when it expires. I have obtained several domain names in this manner. NameJet is an example of a company the buys and sells expired domain names.

What is a subdomain?

A subdomain is an extension of your domain name. For example, say your domain name is boblindquist.com. Since you already own that domain name, you can create names such as games.boblindquist.com or even card.games.boblindquist.com and direct them to where you choose. If you own a good name, you can create many useful subdomains for different purposes at no additional cost.

About Name Servers

When you purchase web or email hosting, you are usually provided with something called a nameserver address. You log on to the web site of your registrar and for each of your domain names you can specify the nameserver address.

A nameserver is kind of like a directory of information about your domain name. The nameserver will tell other computers about where to find resources for that particular domain. For example, when you visit www.boblindquist.com your computer first looks up the nameserver for the domain boblindquist.com. It then asks for the additionalddress of "www.boblindquist.com". The nameserver replies back with the address to connect with to view the web site. When you send an email to someone, the mail server asks the nameserver where to direct the email to for a particular domain name.

Do not mess with your nameserver settings unless you are instructed by someone competent or you know what you are doing, as changing them to incorrect values can result in your email not arriving and your web site not being accessible.

Nameservers maintain several types of records. Your technical staff or consultants should be the only people that ever need to interact on this level. The following three record types are most likely the only ones you will hear of:

A record - Points a particular name to a particular address
MX record - Tells where email should be directed when it is sent
TXT or SPF record - Often used as a mechanism of outgoing spam control

When you purchase web hosting or email hosting you will be given the address of the nameservers for that particular company. Normally, all you have to do is put in those values in the correct place on your registrar web site and your web and email traffic will start heading to the right place.

Why is there a delay in changing over web hosting/email service?

Sometimes when switching nameservers or other records there can be a delay before the new values take effect. Say you have web hosting with one company and you decide to switch to another. When you change the nameserver address anyone who looks up that domain should be directed to the new server.

Years ago it could take 24-36 hours for your nameserver changes to take effect. Most registrar web sites still tell you it may take that many hours. In my experience of late, the changes take effect almost immediately.

You may be familiar with the concept of a "cache". Depending on the settings on your computer, your web browser may cache items from pages you visit. For example, if you visit the same news site every day, the logo from that site may be cached. Using a cache allows your computer to save time by keeping a local copy of something instead of having to retrieve it over the Internet.

Your internet service provider has their own DNS server which handles the dirty work of keeping track of what domain name corresponds to what IP address. If you or someone else that uses your ISP has recently visited a site, your internet service provider may cache that address. A lot of people probably visit CNN.com, so instead of having to get the address for CNN.com every time someone types it in, they keep a copy resulting in faster access to the site. Since nameserver addresses do not change very often, this is reasonable.

If you have recently visited your own site, then your internet service provider may have cached that address. You can go ahead and change the nameserver for your domain and if you type it in and try to visit your site it may still be pointing to the old server. The only recourse is to wait until the record "expires" and then your internet service provider’s DNS server will look up the new address.

Modern operating systems (Windows, Mac OS X, Linux) will also keep their own cache. The idea behind the cache is to reduce network traffic and make your experience faster. Why would your computer call out to a DNS server if it just visited the site 5 minutes ago? Is the address likely to have changed? Well, sometimes they do change and sometimes it is the DNS cache on your local computer that can cause the delay. There are commands you can type in on your computer to clear your local DNS cache.

It can be frustrating when you are moving to a new web hosting service and it results in downtime for your site. In many cases this can be avoided, but as you can see there are numerous factors that can cause delays. While many people may be able to access your new site/host immediately, in certain areas there can be delays.

Transferring Domain Names

The final topic I want to touch on is the transferring of domain names. There are many reasons why you may want to transfer your domain name to another person or to another registrar. The person who built your web site may have registered the domain name in their own name and perhaps you want to move on to another company and build a new site. You obviously want to keep yourname.com as that is on your business cards and other printed materials. You must arrange a transfer of the domain name. If you sell your business to someone else, they will most likely want the domain name to go along with it. In that case you would need to transfer the domain name to them. You should always make sure to have all of the details specified when engaging in such a transaction. Be aware that someone who owns a domain name does not have to cooperate. It is always better to ask nicely and make sure that domain names are included with a sale or other business transaction.

Transferring a domain can be a painful process. Having done many domain name transfers, I felt it would be helpful to explain the basics. Transferring a domain name should not be very easy, if it were people would steal each others domain names more often. The hurdles you have to jump over are there as security precautions to prevent a domain name from being transferred from an unwilling party.

If you have recently registered or transferred your domain name, the registrar may not allow you to transfer it again until a certain time period has elapsed. If that is the case, just wait it out.

You can also transfer a domain name from one registrar to another for your own purposes. Say you register your domain name with GoDaddy and decide you want to switch to another registrar, you can move your domain to another registrar using the transfer process.

The owner of the domain name needs to log in to the web site of their registrar, find the domain name they are going to transfer. They need to make sure the domain name is "unlocked" and able to transfer. This may be called registrar-lock or clientTransferProhibited. They must then request an authorization code. There is usually a button or link that allows you to do this. The owner of the domain must provide you with this code. The registrar they use can provide assistance in "unlocking" the domain and requesting the authorization code.

The person who is receiving the domain name must then go to the registrar of their choice and initiate a transfer. You enter in the domain name you are transferring and then it will prompt you for the authorization code. You enter the code that was provided and the transfer is started. The registrar will then prompt you for your existing account with them or have you create a new account and enter in some personal information and billing information.

The owner of the domain will then receive an email (it usually takes a few days) asking them to confirm that they wish to transfer the domain name. Sometimes the email will require them to visit a link and approve it, sometimes it just tells them if they take no action the transfer will go through. The content of the email will vary slightly depending on the registrar. An important note, the email will be sent to the email address listed in the WHOIS record for the domain. If that address is no longer valid, or is under the control of someone else, that can be a problem. Explaining the steps to deal with a situation like that is beyond the scope of this article. In that case I would recommend consulting a professional to try to get the issue resolved.

If everything goes smoothly, and everyone does what they are supposed to, in my experience it usually takes about a week for a transfer to occur. If you are transferring a domain name from one account to another and you are using the same registrar, it can occur much quicker. Transferring between accounts on the same registrar can take sometimes take place in one day.


While we overlooked many technical details, you should now have a basic understanding of the domain name system. If you hire competent consultants/staff you may never have to deal with the DNS system. Knowing the basics of how it operates can avoid confusion later. Before beginning almost any web site project, I find the need to explain one or more aspects of this system to the client. My hope for this article is to help educate you on some of the basics and provide you with information on how to protect your domain names from those nefarious characters out there who would love to take them away.

About the author

Bob Lindquist is an expert consultant with extensive experience building web sites, databases and performing internet marketing work for his clients.  He has over 20 years of experience working with clients from a wide variety of industries along with a degree in Computer Science.  Bob is a professional member of the Association for Computing Machinery.

In his free time, Bob is a volunteer Firefighter / EMT and has served on the boards of several not-for-profit groups.

If you are interested in talking about a potential project, use the contact form on www.boblindquist.com